挑战习题
1/5单选题
难度:

1.关于无线电波的主要用途,下列说法正确的是(  )
A 收音机用中波
B 超远程通信只能用微波
C 电视机发射、接收用的是长波
D 移动通信用中短波
提示1:
5LqG6Kej55S156OB5rOi55qE5bqU55So
正确答案:QQ==
QeOAgeaUtumfs+acuueahOmAmuS/oeeUqOS4reazou+8jOaVheivpemAiemhueato+ehru+8m0LjgIHotoXov5zpgJrkv6Hlj6/nlKjnn63ms6LvvIjlpoLlm73pmYXlub/mkq3vvInjgIHkuK3plb/ms6LvvIjlpoLmvZzoiYfpgJrkv6HvvInvvJvmlYXplJnor6/vvJtD44CB55S16KeG5py65o6l5pS26LaF55+t5rOi77yb5pWF6ZSZ6K+v77ybROOAgeenu+WKqOmAmuS/oeeUqOefreazou+8iOS+i+Wmgua1t+S4iuiIueWPqumAmuS/oe+8ieOAgei2heefreazou+8iOS+i+WmguWvueiusuacuuOAgeenu+WKqOeUteivne+8ieOAgeW+ruazou+8iOS+i+WmguWNq+aYn+eUteivne+8ie+8jOaVhemUmeivr++8juaVhemAiUHvvI4=